hdu 3746 Cyclic Nacklace (KMP求最小循环节)

//len-next[len]为最小循环节的长度
# include <stdio.h>
# include <algorithm>
# include <string.h>
using namespace std;
int len;
char a[100010];
int next[100010];
void Getnext()
{
int i=0,j=-1;
next[0]=-1;
while(i<=len)
{
if(j==-1||a[i]==a[j])
i++,j++,next[i]=j;
else
j=next[j];
}
}
int main()
{
int t;
while(~scanf("%d",&t))
{
while(t--)
{
scanf("%s",a);
len=strlen(a);
Getnext();
int ans=len-next[len];//最小循环节
if(next[len]==0)
printf("%d\n",len);
else if(len%ans==0)
printf("0\n");
else
printf("%d\n",ans-len%ans);
}
}
return 0;
}